Electric valve operator



D. J. STEWART 1,903,230 ELECTRIC" VALVE OPERATOR l Filed July 1s, 1929 2sheets-sheet 1 March 28,` 1933.

March 28, 1933. D. J, STEWART 1,903,230

ELECTRIC VALVE OPERATOR Filed July 13, 1929 2 Sheets-Sheet 2 l 0 l `z ToLINE Ac 35 I A l INVENToR f Banaan J Stewart.

ATTORNEYS Patented Mar. 28, 1933 UNITED STATES PATENT ori-'ICE Duncan J.srxwnr, or mcxroan, rumors, Assmnoa'ro nowm n. comun, or

, noon-onu. rumors mmc VALVE OPERATOR Application led July 13,

The invention relates to an electric valve operator and has moreespecial reference to an operator driven by a rotary electric motor andadapted for use upon heatcontrol valves of the type employed incontrolling the flow of a heating medium to a radiator.

'lhe primary object of the invention is to provide a practical electricvalve operator of the character indicated, which by reason of its smallsize may be mounted in closely restricted spaces directly on the valveto be operated; which is substantially noiseless in its operation; andwhich is entirely reliable over long periods of time without attention.

I am aware that many attempts have heretofore been made to produceelectric valve operators employing rotary motors, but motors of theordinary type, such as have heretofore been employed, fail to meet therequirements and have not come into commercial usage. Chief among theobjections to such prior motors is that they must, if capable of'supplying sufficient power, be made so large as to render the operatingstructure wholly unsuited to application to radiator control valves.Moreover, they commonly use commutators whose brushes are a constantsource of diilculty and annoyance.

With. these objections in view, I employ in my improved operator aninduction motor of the shading ring type having-a stator or field memberin the form of a lat open frame. A squirrel cage rotor is mountedtransversely of one side member of the frame, and the side member remotefrom the rotor carries the energizing coil. Such a motor may be made ofvery small dimensions and yet be capable of delivering ample power forthe operation of the valve. Also I have found its shape to beadvantageous in that it lends itself readily to incorporation in a smallcompact structure.

In carrying out my invention, I employ a relatively `small supportingframe adapted to be secured directly on the valve casing. Centrallydisposed within this frame is a reciprocable valve actuator having anoperative connection with a transversely disposed actuating shaft. Theshaft is driven through 1889. Serial No. 878,118.

a torque multiplying spur gear train from the motor, the latter beingositioned at one side of the actuator, with t e gear train on theopposite side. A control mechanism for determining the valve opening andclosing cycles is o eratively associated with the actuating sha t in aconveniently accessible position. Thus the overall lon itudinal andlateral dimensions are proper y coordinated with reference to thecharacter of the spaces ordinarily provided for radiator control valves,and the entire unit, together with an enclosing cap or cover, requiresno greater space than that consumed in many instances by ordinary handoperators.

In the accompanying drawings I have illustrated an operator of thepreferred construction and arrangement, although it will be understoodthat various changes may be made without departing from the spirit andscope of the invention as expreed in the appended claims.

Figure 1 of the drawings is a perspective view of my improved operatorwith the enclosing cover removed, the operator being shown secured to aradiator control valve.

Fig. 2 is an elevational view of the operator looking from the sideopposite that shown in Fig. 1 and showing the removable cover insection. v

Fig. 3 is a plan view of the operator, the cover being shown intransverse section.

Fig. 4 is a detail view of a part of the switch mechanism.

Fig. 5 is a fragmentary'vertical sectional View on an enlarged scalethrough the motor.

Fig. 6 is a fragmentary vertical sectional view taken approximately inthe plane of line 6 6 of Fig. 2.

Fig. 7 is a central vertical sectional view through the operator and thevalve.

Fig. 8 is a schematic view showing the control mechanism with theprincipal parts of the operator in perspective.

The valve to which the operator is applied comprises as herein shown acasin 10 having an inlet 11 and an outlet 12. A va ve member 13 isreciprocable axially toward and from a. seat 14 in the casing, the valvemember having an operating stem 15 projecting through an opening in onewall ofthe easing, which openwhich isclampedi'betiween the cap 16 andthe easing 10.

The plate 18 has a central aperture 19 thereirl through which the stem15 projects, and the cap 16 similarly has an aperture 20 farmed in acentrally depressed portion 21 adapted to receive a packing ring 22. Thelatter may be held in position by means of a spring ring A plurality ofvent holes 24 are provided in the cap 16 to permit the escupe of anysteam and vapor which may leak past the diaphragm 17 such steam or vaporbeing prevented from escaping from the cap around the valve stem by thepacking ring 22. y

The operator in the preferred embodiment comprises in general anelectric motor 25, a maiuoperating shaft 26, a torque multiplying geartrain 27 connecting the motor shaft with the main shaft, a reciprocableactuator 28 operatively associated with the main shaft and connectedwith the valve stem 15, and a controlling switch mechanism 29 foreffecting successive valve opening and closing movements in alternatecycles. Of these several elements, the reciprocable actuator 28constitutes' a cent-ral axis relative to which the other elements aresymmetrically arranged to form a small compact operating unit of properlongitudinal and transverse dimensions.

Referring now to the preferred arrangement employed, the reciprocableactuator 28 is connected at one end to the axial valve stem 15 so as toform an extension thereof; and the main operating shaft 26, which isoperatively associated with the opposite end of the actuator, isdisposed in perpendicular relation thereto.

ltion set forth, a frame is provided consisting of a circular base plate30 and a pair of upstanding side plates 31 and 32. The latter aresecured at their lower ends to lugs 33 struck up from the base plate,and are connected at their upper ends by tie rods 34, with blocks 35 and36 of suitable insulating material interposed between theplates andconstituting spacers.

The two side plates 31 andc32 provide bearings for the opposite ends ofthe main oper.

ating shaft 26, and an additional bearing member is provided in the formof a smaller intermediate plate 38 which is preferably made ofnon-magnetic material. This late 38 is secured at its lower end to astruc up lug 39 on the circular base plate, and is connected at itsupper end to the-main side plate 31 as by means of a bolt 40 with aspacer sleeve 41 interposed between the plates 30 and 31. The plate isspaced only a short distance from the side late 31 so as to receivebetween it and sald side plate a portion of the motor 25. Also the plate38 coacts with the opposite side plate 32 to provide bearings forsupporting the gear train 27.

The base plate 30 is adapted to be secured upon the upper flat face ofthe valve cap 16, which has a peripheral flange 42. Fastening screws 43are entered through the base plate and threaded into the flange of thevalve cap. When the operator is secured in position upon the valve, thestem 15 projects centrally into the lower portion of the supportin rame, a central aperture 44 being provi ed in the base plate 30.

The motor 25 comprises a relatively flat eld member or stator 45 oflaminated construction. It is in the form of an open substantiallyrectangular frame, one side member of which is constructed to providetwo opposed poles 46 and 47 (Fig. 6) between which is mounted a rotor 48of the squirrel cage type. The opposite side portion of the stator framecarries an energizing field coil 49 which is therefore positioned inlaterally offset relation to the rotor. The poles 46 and 47 are in thepreferred embodiment connected by integral bridging members 50, and eachof the poles is equipped with two shading coils 51 and 52.

The motor as thus constructed may, by analogy to so-called core typetransformers, be said to be of the core type, and while the motorstructure forms no part, per se, of the present invention, it ispeculiarly adaptable in its general characteristics to incorporation inthe improved operator. Thus, whereas electric rotary motors of the morecommon variety must, in order to develop suiicient power to effect thedesired operation, be made large and cumbersome in size, the presentmotor has relatively highstarting and stall torques, and is capable ofdeveloping ample power for purposes of valve operation even when made ofvery small dimensions. The flat type of neld member, with its laterallyoffset energizing coil, and with relatively small shading coils, givesto the motor a shape such that it may be incorporated advantageouslydirectly within a small symmetrical operating unit. Moreover, the motoris practically noiseless in operation, and due to the absence of acommutator and brushes it is reliable, even after long periods ofidleness, and resents'no diliiculties from the standpoint o radiointerference.

Preferably the rotor, 48 is mounted in bearing members carried directlyby the stator frame, thus avoiding the use of a long shaft and insuringaccurate centering of the rotor between the poles. As best shown inFigs. 1 and 5, the rotor bearings are provided by two plates 53 and 54of suitable non-magnetic material. The op osite ends of the plates arerigidly secure onopposite sides of the stator frame and thecentral'portions of the plates are offset in a direction away from saidframe and centrally apertured to receive bearing bushings 55. Thelattermay be of any preferred character, those herein shownbein'gequipped with oil pockets 56 which need be filled only initiallyto cover the wearing-in period. 4

The motor is supported between the side plate 31 and the intermediatebearing plate 38, and for this purposethe rotor bearing members 53 and54 are provided with outwardly projecting annular flanges 57 which bearin apertures 58 and 59 formed respectively in the plates 31 and 38. Saidflanges further serve to provide elongated apertures in the plates 53and 54 for the bushings 55. The motor is held against turning by theengagement of a portion 4of the spool of the main iield coil 49 in anotch 60 formed in the side plate 31.

The rotor shaft 61 extends through thebushings 55, and one projectingend thereof carries a spur pinion 62 forming part of the gear train 27.The spur pinion 62 thus meshes with a spur gear 63 fast on a shaft 64vthe opposite ends of which are respectively journaled in the bearingplate 38 and the side plate 32 (Fig. l). referably the spur gear 6i:made of non-metallic material and is made fast upon the shaft 64 bymeans of a metallic disk 65. l

lso journaled. in the side plate 32 and the intermediate bearing plate38 is a shaft 66 having rigid therewith adjacent the plate 32 a spurgear 67 meshing with a pinion 68 formed integral with the shaft 64. Theshaft 66 in turn has a pinion 69 meshing 'with al spur gear 70 fast onthe main operating shaft 26 at the end thereof adjacent the plate 32.

The gear train 27 thus constitutes a threestep gear reduction betweenthe motor shaft and the main operating shaft, and between latter shaftand the valve actuator is interposed an operative connection such thatin successive half revolutions of this shaft 26 the valve is alternatelyopened and closed, the rotary motion in the shaft being converted intoreciprocatory motion in the actuator 28 and the valve stem 15. The useof spur gearing for connecting said two shafts is ad vantageousespecially in an operator ernployed for heat control purposes wherelubrln cation diculties are encountered. Thus the y spur type gearingavoids end thrusts and s1m1lar wearing actions incident to other 26 andcoacting with two follower rollers 7 2 and 73. The latter are mounted inthe actuator on diametrically o ggsite sides of the cam, and aresupporte tween two lates 75 spaced a short distance apart andongitudinally slotted to form ides coacting with the shaft 26 in thelengt wise movement of the actuator.

A yielding lost motion connection is provided between the actuatorandthe vvalve stem 115, of a character such that at-the end of the valveclosing cycle the valve member is held to its seat with a predeterminedyielding pressure. To this end the lower end of the actuator isconstructed to form a .tubular stem 77. Thus it is made in two segmentsrespectively integral with the plates 75 at the upper end of theactuator. The lower end of the stem 77 is closed by a fixed cap 78 whichserves to hold the two segments together, and within the tubular stem isa coiled expansion spring 79 bearing at its lower end upon a washer 80.In the assembled relation of the parts the Washer 80'bears upon theupper end of the valve stem 15, and the latter is transversely aperturedto receive a bolt 81 the ends of which pass through slots 82 inoppositeside wallsof the stem. The slots 82 are of a length such that'after thevalve member, in the closing cycle engages its seat 14, the actuator ispermitted to continue its movement as the spring 79 is compressed.

It will be observed that the operator as a. whole may be removed fromthe valve by removing the screws 43 and disconnecting the actuator 28from the valve stem 15, the latter being accomplished by removing thebolt 81. When the operator is removed the washer 8O engages with theinturned flan e of the cap 78 and retains the spring 79 within thetubular stem 77. Moreover, such removal of the operator may beaccomplished without opening the valve 10 to the atmosphere, the sealbeing maintained inasmuch as the c'ap 16 remains in position.

The switch mechanism 29 for governing the valve opening and closingcycles forms per se no part of the present invention. Briefly itcomprises Fig.'8) three switches 83, 84 and 85 re'spect1vel operable bycams 86, 87 and 88 on the sha t 26. The cams 86 and 87 have oppositelydisposed flat sides, while the cam 88 for the running switch has twodiametrically disposed notches 88n as shown in Fig. 6.

The switches 83 and 84 constitute starting 'switches coacting with twoswitches 89 and 90 of a suitable thermostatto initiate valve opening orclosing cycles respectively. The switch 85 constitutes a running s'witchand 5 is operable independently of the thermostat after the cycle hasbeen initiated by one of the starting switches. y

The movable contact of each of the switches 83,84 and 85 is carried onthe -free l0 end of a resilient arm 91 and the three arms are anchoredon a metallic chamel member 94 secured to the insulated block 36 (Fig.6).

Each of the stationary contacts of said switches 83,84 and 85 is mountedin a plug 95, and the several lugs are embedded in the fibre block 35and respectively connected electrically to the three switch contacts ofthe thermostat. The intermediate or common contact of the thermostat isalso coni0 nected to the grounded secondary 92 of a transformer havingits primary 93 connected to a source of alternating current. The threemovable switch arms 91, made electrically common through the metallicchannel member 94, are connected with the main field coil 49, the latterbeing grounded.

With the parts in the relation shown in Fig. 8, the starting switch 83is closed and when the thermostat switch 89 is closed, the 39 coil 49 isenergized and the motor operated.

In the initial portion of the movement of the shaft 26, the runningswitch 85 is closed,

and the cycle is terminated by the opening of the running switch 85after one-half revolution of the shaft 26. At this time the startingswitch 83 is also opened, and the starting switch 84 is closed ready forthe next operating cycle subject to the control lof the thermostatswitch 90.

In addition to the switches 83, 84 and 85, two switches 97 and 98respectively controlled by cams 99 and 100 are shown, so that in allfive switches are controlled by as many cams all on the operatin shaft26. The two switches 97 and 98 may e employed in the control of anothervalve operator without the use of a separate thermostat, as fully setforth in the application of Howard D.

Colman, Serial No. 361,302, filed May 8, 1929. The movable switch armsfor the switches 83, 84, 85, 97 and 98 are operated by their respectivecams through the medium of follower rollers 101 (Fig. 4). Theconstruction shown comprises two plates 102 of insulating materialbetween-which the roller 101 is mounted, the upper ends of the platesbeing slotted to receive laterally extending lugs 103 formed integrallywith the contact arm. Said arm being made of hardened l0 spring steel,does not permit of convenient bending, and the plates. 102 are thereforeclamped in position by means of a separate plate 104 of relativelysofter material. Said plate 104 underlies the contact arm and has atopposite edges lugs 105 passing through slots in the plates and bent'downwardly into engagement therewith.

It is desirable that the operation of the motor be stopped quickly atthe endof each operating cycle, at which time' the running switch is inopen position with the roller follower 101 seated in onev of the notches88'* of of the cam 88. These notches are made relatively short so as toreduce to a minimum the time during which the current flows through thethermostat contacts, and it is essential that the motor be stopped afterthe running switch has been opened. Also it' is desirable that theactuating cam 71 for the valve be shaped to provide only a short dwellatthe end of the closing cycle, and if the operator is not stopped uponthis dwell the spring 79, being under substantial tension, would have atendency to rotate the operating shaft in one direction or the othersufficient to permit leakage of steam past the valve or to close therunning switch 85.

I therefore provide an electric brake which is operable as an incidentto the energization and de-energization of the field coil 49, and inorder to avoid the use of a separate especially constructed alternatingcurrent brake magnet, which would consume a substantial amount of spacein the operator and which would add substantially to the cost thereof, Iutilize a solenoidal action of the motor field upon the rotor. Thusreferring to Figs. 1 and 5, the rotor of the motor is mounted so as tobe capable of a limited axial movement, the spur gear pinion 62 beingmade of sullicient length to permit such movement while maintaining thedriving connection. A leaf spring 106 is secured to the outer side ofthe side plate 31 with its free end bearing on the outer end ofthe rotorshaft 61 in a direction to force the rotor toward its bearing plate 54.Preferably a libre washer 107 is interposed between the rotor and saidplate 54 to provide better frictional surfaces.

When the motor is energized at the beginning of a cycle, therotor movesaxially toward its magnetic center in the stator under a. solenoidalaction .of suliicient strength to overcome the tension of the spring106. Upon the de-energization of the motor, the spring acts to returnthe rotor, exerting a braking pressure on the bearing plate 54 throughthe medium of the washer 107. Since the brake utilizes the sameelectromagnetic means as the motor, it consumes little or no additionalspace and does not add appreciably to the cost of the construction.

The entire operating unit is conveniently enclosed by a cylindrical capor cover 108 which is seated at its lower end upon the flange 42 of thecap 16, said flange being of a diameter slightly larger than the framebase plate 30. Within the lower end of the cap is a metallic band 109carrying at spaced intervals pins 110 (Fig. 7) adapted to inter-1,aoa,aao

lock' with'bent lugs 111 struck up from the I base plate 30, theinterlocking action being obtained b a sli ht twisting of the caprelativeto the asep ate. p

^ It will be observed that b l the construction and arrangement providthe motor consumes only' a relatively small rtion of the space withinthe frame, being on the one hand between the central reciprocatoryactuator and the adjacent side plate, and on the otherhand between the oshaft and the base late;l Thus'ampl'e s ace is provided upon foppoaiteside ofe actuator for the multiplying gear'train, andvv for theswitch mechanism advantageonsly the space above the motorbetweenthe two?side plates ofthe frame. Moreover, the vgearl supporting-shafts 66 areof substantial lengthfwithat each end".r` in l slight irregularities1Q-mounting 'of' these shafts does not affect material] l' the properintermeshing of the: gears, there is no tendency t'o wear outof'alinement with a sultant chatter o f the y gears', as where theshafts are supported at one end only.

I claim asv my invention:

1. An electric valve operator comprising, in combinationv with a valvehaving a reci rocable operating stem projecting axial from the casing, amain frame comprising a base plate adapted to be secured to said cas--ing and having a central aperture through which said valve operatingstem projects, said frame further comprising a pair of laterally spacedsubstantially parallel side plates secured at their lower ends to saidbase plate, a main operating shaft having its opposite ends mounted insaid plates in parallel relation to the base plate but spaced asubstantial distance therefrom, a reciprocable actuator connected to andaxially alined with said valve stem, said actuator having an operativeconnection with said main operating shaft so as to be reciprocable inthe rotation of said shaft, an electric motor comprising a stator in theform of a substantially fiat open frame with a rotor mountedtransversely of one side member of the frameand an energizing coilmounted on an opposite side member, said motor being disposed withinsaid main frame between said actuator and one of said side plates, amultiplying gear connection between the rotor and said operating shaft,and a controlling switch mechanism supported between the upper ends ofthe side plates and above the motor, said operating shaft having meansfor actuating said switch mechanism. 2. An electrically driven operatorfor radiator valvesvand the like comprising, in combination, a framehaving a base plate, a pair of laterally spaced side plates and arelatively smaller intermediate plate spaced a short distance from oneof said side plates, an electric induction motor having a stator in theform of a relatively fiat frame mounted between said intermediate plateand the "ad-'a- 'cent side late, a central actuator lsposed between saidintermediate 4plate andthe opposite side plate, said motor avingl arotor mounted transversely of the stator frame with a drivingshaft'projecting through said intermediate late, a main operating shaftmounted in sai side plates above the motor and operativel connected withsaid actuating-member, an a s ur gear train rotor shaft with saidoperating sha t Y e 3,v An electrically driven operator for radiatorvalves and the like` comprising, in combination, a frame having a baselate"`a pair of'l'aterally spaced side plates an a ativelysmallerintermediate plate spaced from onel of side plates, an electricinduction motorliaving astatorfin the form of a relatively flat framemounted between saidinter mediate plate and the adjacent side plate, acentralY longitudinal valve actuator disposed between said intermediateplate andthe oppositesi'de"v plate, said motor having a rotor mountedtransversely of the stator frame witha driving shaft projecting throughsaid intermediate plate, a main operating. shaft mounted in said sideplates above the motor and operatively connected with saidaetnat ingmember, and a spur gear train connecting said rotor shaft with said opershaft, said spur gear train having a pini of operating shafts mountedbetween salintermediate frame member and the sida piate remote from themotor.

4. An electrically driven operator for radiator valves and the likecomprising, in ccmbination with a reciprocable valve operating stem, areciprocable actuating member alined with and having a yieldable lostmotion connection with said stem, a main operating shaft having a camthereon, a pair of cam followers on said actuator disposed op positesides of the cam, a rotary eectric motor having an energizing fieldccmotor and said main operating si" means operatively associated withating shaft and adapted in the unisi x rotation of the cam to eect saccaive valve opening and closing cycles, said cam having a relatively shortdwell acting through said yieldable lost motion connection to heid thevalve member in closed position with a predetermined yielding pressureand a brake operable as an incident to ergization and de-energization ofthe ield coi?. and adapted to stop said cam with its dweli engaging oneof said followers in 'the closed position of the valve.

5. An electrically driven operator for radi ator valves and the iikecomprising a vaive actuator, a main operating shaft operativelyconnected with said actuator, an electric induction motor having astator in the form of ongitudinal va. ve

a fiat frame and an axially movable rotor having a shaft rotatableunidirectionally in the operation of the motor, a. torque multiplyingconnection between said shafts, a controllin switch mechanism operableto define successive valve opening and closing cycles, and anelectricbrake comprising a stationary friction surface, and spring meanstending to move said rotor'into frictional engagement with said surface,said rotor being` movable in the opposite direction to release the brakeas an incident to the energization of thev motor winding. i 6. Anelectrically driven i valve operator comprising a lsupporting frame,valve actuating means including a rotary element mounted insaid frame,and'a vcombined elec-` tric motor and brake unit also mounted in saidframe and including anA axially' movable,

rotor, a brake and a ,single electromagnetic means adapted whenenergized to .produce a magnetic field which causes rotation of saidrotor andr moves it axially in a direction to release said brake,saidrotor having a gear;

ing connection with said rotarv element.

adapted to permit of such axial movement of the rotor.

7. An electric motor-driven operator for radiator control valves and thelike comprising, in combination, a base plate,an operating shaft mountedparallel to said plate in spaced relation thereto, an electric motorcomprising a flat land relatively thin stator base plate and two sideplates rigidly sup-y ported in spaced relation at opposite' sides of thebase plate, an operating shaft mounted at opposite ends in said sideplates and disposed parallel to but spaced from the base plate, anelectric. shading ring motor having a flat core type stator verticallydisposed in" said frame between the base plate and the operating shaftand having two spaced legs with an energizing coil en one leg and arotor in the other, said rotor being disposed parallel to said operatingshaft, a spur gear train mounted in the frame and providing a torquemultiplying gearing connection between said rotor and said shaft, and aswitch mechanism operatively associated with said shaft for controllingsaid motor.

9. An electrically driven valve operator comprising, in combination, aframe havingl a basefplate and two side plates rigidly supported inspaced relation at opposite sides ofy the base plate, a shaft mounted insaid frame parallel to but spaced from the base plate,

an electric shadinglring motor having a flat, i

core type stator vertically` disposedin said frame in offset relation to=thecenter of the other disposed parallel to said shaft, a spur t,;

gear train mounted inthesframe `adjacent the "f other side'plate andproviding a torque multor and said shaft, acam fast on said shaftcentrally thereof, and a reciprocatory valve actuator operativelyassociated with said cam and disposedfbetweensaid motor and said geartrain. e

10. lAn electrically driven operator for Ivalves of the type comprisinga body and a f5'. tiplying gearing connectionrbetweenfsaid ro-.

valve member reciprocable axially toward and 1.

from a seat in said body, said operator comprising a supporting frameadapted to be mounted upon the valve body in projecting relation to oneside thereof, a reciprocatory valve actuating stem disposed centrallywithin said frame in axial alinement with the valve member to beoperated and adapted for connection therewith, an operating shaftmounted in said frame transversely of said stem, means operativelyconnecting said shaft with the stem adapted to impart a reciprocatorymovement to the stem in the rotation of the shaft, an electric shadingring motor having' a core type stator in the form of a thin flat framemounted in said supporting frame and disposed adjacent one side of saidstem in parallel relation thereto, a rotor rotatably supported on saidstator frame, and a torque multiplying gear train between the rotor andthe operating shaft and disposed on the side of the actuating stemopposite the motor.

In testimony whereof, I have hereunto affixed my signature.

DUNCAN J. STEWART.

ilo

